Mr Justice Stephens, sitting at Belfast Crown Court, imposed the 20-year jail term, saying there is a clear need to deter other terrorists.

“There should be a clear message to others that no matter how long is the time that elapses and no matter what changes occur in a terrorist’s way of life, that condign punishment will be imposed for committing such offences once they have been brought to justice,” the judge said.

“There is a continuing and compelling need to deter all other potential terrorists.”